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MITOSIS AND MEIOSIS FURTHER ANALYSIS
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Mitosis Questions
1. What is the overall purpose of mitosis?
To produce more identical somatic cells.
2. Give examples of why an organism might need to be able to produce more cells.
Growth of an organism. To heal injuries. To prevent the cell from becoming too large.
In the space provided, write the letter of the description that best matches each term.
3. E__ First gap (G1) phase
A. division of the nucleus
4. D__ Synthesis (S) phase
B. cytoplasm divides and daughter cells become physically separated
5. C__ Second gap (G2) phase
C. final preparations are made for the cell to divide
6. A__ Mitosis
D. DNA is copied
7. B__ Cytokinesis
E. cell grows and carries out its routine functions
8. What function do spindle fibers perform during mitosis?
They attach to chromosomes, moving them to the middle (metaphase) and then pulling them apart
(anaphase)
9. What function do centrioles perform during mitosis?
They produce spindle fibers.
In the space provided, write the letter of the description that best matches each term.
10. __C__ Prophase
11. __B__ Telophase
12. __A__ Metaphase
13. __D__ Anaphase
a. Chromosomes align in center of cell.
b. Nuclei reform. Chromosomes unwind. Spindle fibers break down.
c. Chromatin condenses into chromosomes. Nucleus disappears.
d. Chromatids are pulled by spindle fibers to opposite poles of the cell.
Complete each statement by circling or highlighting the correct term or phrase in the brackets.
14. Cytokinesis takes place [ prior to / following ] mitosis.
15. During cytokinesis in animal cells, a cleavage furrow is formed by [ a cell wall / a belt of proteins ].
16. In plant cells, a new cell wall is formed by [ vesicles / cell plates ] holding cell wall materials.
17. Following cytokinesis, the new daughter cells enter the [ G1 / G2 ] phase of [ prophase / interphase ].
18. Mitosis results in [ two / four ] daughter cells which are genetically [ identical to / different from ] the parent.
19. In the space below, draw a chromosome and label the following terms: chromosome, chromatid, centromere.
Chromatid
x
Chromatid
Centromere
Chromosome
Meiosis Questions
In the space provided, write the name of the stage of the Meiosis cell cycle that is being described.
1. Anaphase II
The chromosomes divide, and the chromatids move to opposite poles of the cell.
2. Interphase
Takes place prior to meiosis I, DNA is duplicated.
3. Telophase II
Nuclei reform in all four daughter cells. Chromosomes unwind back into chromatin.
4. Anaphase I
The homologous chromosomes separate. Full chromosomes are pulled to the poles.
5. Prophase I
Chromosomes form. Homologous chromosomes pair up and crossing over occurs.
6. Prophase II
Both nuclei disappear and chromosomes condense in each cell.
7. Cytokinesis
Takes place following meiosis II. Results in four sperm or one mature egg cell.
8. Metaphase II
Chromosomes line up single file along the middle of each cell.
9. Telophase I
Two nuclei reform. Results in two haploid daughter cells.
10. Metaphase I
Homologous chromosome pairs attach to spindle fibers and align in the middle of the cell.
Complete each statement by circling or highlighting the correct term or phrase in the brackets.
11. The purpose of meiosis is to produce [ diploid / haploid ] [ somatic / gamete ] cells.
12. In the production of sex cells, DNA is duplicated [ once / twice ] and the cell divides [ once / twice ].
13. The pairing up and crossing over of homologous chromosomes takes place in [ interphase / prophase I ].
14. In metaphase I of meiosis, chromosomes line up [ in homologous pairs / single file ].
15. Meiosis results in [ two / four ] daughter cells which are genetically [ identical to / different from ] the parent.
16. How are metaphase I and metaphase II of meiosis different from one another?
In metaphase I, chromosomes line up in homologous PAIRS. In metaphase II, chromosomes line up single file.
17. How are anaphase I and anaphase II of meiosis different from one another?
In anaphase I, full chromosomes are being pulled to the poles. In anaphase II, chromatids are being pulled to
the poles.
18. Describe crossing over. How does crossing over benefit an organism?
Crossing over is an exchange of genetic information which takes place in Prophase I. Crossing over produces
genetic variation.
19. Compare and contrast spermatogenesis and oogenesis.
Spermatogenesis is the production of sperm, oogenesis is the production of eggs. Both sperm and eggs are
haploid gametes. In spermatogenesis, four mature sperm are produced in the testes. In oogenesis, four cells
are produced in the ovaries but only one matures into an actual egg cell.
Mitosis vs. Meiosis Questions
Fill in following tables for Mitosis and Meiosis…
MITOSIS
MEIOSIS
Purpose of process
To produce somatic cells.
Diploid  Diploid
To produce gametes (sex cells).
Diploid  Haploid
Type of parent cell
(haploid or diploid)
Diploid
Diploid
Chromosomes of parent cell
(haploid or diploid)
Same as above
Same as above
Type of daughter cell
(somatic or gamete)
Somatic
Gamete
Chromosomes of daughter cells
(haploid or diploid)
Diploid
Haploid
Number of daughter cells following
the complete process
2
4
Number of times DNA replicates prior
to cell division
1
1
1
2
Number of times nucleus divides
EVENT
MITOSIS
MEIOSIS I
MEIOSIS II
Does crossing over occur?
(yes or no)
No
Yes
no
How do chromosomes line up in
the middle during metaphase?
Single file
In homologous pairs
Single file
What separates in anaphase?
Chromatids
Full chromosomes
Chromatids
Do homologous chromosomes
pair up in prophase?
No
Yes
no
No
Yes
yes
Is genetic variation produced?
Application Questions
1. Explain the connection between mitosis and cancer. How does your body try to prevent cancer from forming?
Cancer results when cells no longer receive the signal to stop dividing. In other words, cancer is uncontrolled
mitosis. Apoptosis (programmed cell death) is one way your body prevents cancer from forming.
2. The diploid cell of a polar bear has 74 chromosomes.
a. Following mitosis…
74
___
74
74
___
b.
Following meiosis…
Following fertilization….
37
___
37
___
74
37
___
37
___
37
___
74
37
___
3. The **starred** cell in the question above represents a zygote, or fertilized egg.
a. This is also known as the first _________somatic___________ cell.
b. This cell will now begin to undergo which process in order to develop into a baby?
Mitosis
4. An error during mitosis cannot be passed on to future generations. An error during meiosis, however, CAN be
passed on to future generations of offspring. Defend the truth of this statement.
Mitosis is the reproduction of somatic cells. If an error occurs, it doesn’t matter because somatic cells
aren’t passed on from parent to offspring.
Meiosis is the production of gametes, or sex cells. Sex cells are what become people. Therefore, if an
error occurs in meiosis it will be given to the baby when the egg is fertilized.
5. Down Syndrome is a genetic disorder that results when a person’s cells have an extra 21st chromosome (instead
of the normal two 21st chromosomes, there are three). Explain the connection between Down Syndrome and
meiosis.
When eggs and sperm are produced following meiosis, they should each end up with one 21st
chromosome. That way the cell has two when the egg is fertilized. If an egg or a sperm somehow ends
up with two 21st chromosomes, there will be a total of three 21st chromosomes when the egg is
fertilized.
The fertilized egg with three 21st chromosomes will then begin going through mitosis and every single
new cell will also have three 21st chromosomes.